This episode is part two of my in-depth discussion with Dr. Praveen Arany, a world-renowned light therapy (photobiomodulation) researcher and expert who’s been working in the field for over two decades.
If you missed part one, I highly recommend you go back and listen to that episode. We delve into some very deep and specific science around light therapy that will prepare you for everything you hear in part two.
In this episode, we get into the minutiae of light therapy dosing and also talk about a few others topics like systemic vs local effects.
Similarly to part one, this is not well-suited for beginners! If you’re really interested in the topic of light therapy/photobiomodulation, you’ll appreciate this discussion. But if you’re looking for a high-level overview, this is not for you.
If you’re ready to learn more, listen in for a truly comprehensive and research-based take on light therapy dosing.
A quick note: Dr. Arany runs a lab at the University of Buffalo that does research on photobiomodulation, and he’s asked to he’s asked me to share with you a link where you can donate to his research lab so they can continue to do this research and conduct experiments in this field.
Table of Contents
In this podcast, Dr. Arany and I discuss:
- 3 major issues with understanding optimal light therapy doses—are you using the right dose for you and your needs?
- The concept of photon fluence, the einstein measurement, and Dr. Arany’s work within the scientific community to create a standardization for light therapy dosing
- The penetration depth of different forms of light therapy and how this contributes to dosing guidelines
- Why light therapy research outcomes vary in dosing and don’t offer clear recommendations
- The biphasic dose response—sometimes known as the Arndt-Schulz law—explaining why large doses probably don’t cause harm but aren’t as effective as small doses over time
- Good news if you use light therapy at home…it’s likely that you’re getting good results even with an imprecise dose
- Dr. Arany’s 2 predictions about where the field of photobiomodulation will go in the future
- Specific ways to know if the device you’re purchasing is effective…or not
- Factors that affect light therapy dose, such as skin color, sex, body size, the type of device you’re using, and more
- Are EMFs emitted by light therapy devices an issue we should be concerned about?
- The roles of different light wavelengths—green, blue, yellow, and red—in healing
- Can heat created by your light therapy device interfere with the therapeutic effect?
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Transcript
Ari: Dr. Arany, welcome back to the show. Thank you so much for joining me.
Dr. Praveen Arany: Thank you for having me again, Ari. Great to be here.
The biggest issue with photobiomodulation
Ari: We have a lot to talk about still. We’ve talked a lot about mechanisms so far, we’ve gone very deep on that, but there is this sort of, I would say, elephant in the room when it comes to red and near-infrared light therapy. For all the people that have delved into the science very deeply, you arrive at very big questions when it comes to dosing, because there is this fundamental problem. I would say two fundamental problems.
One is that the body of research uses many different types of devices and methods of delivery, which is something we’re going to talk about, and I’d say even more glaringly is you have this issue of radically and related issue, radically different doses delivered to the tissue. Many of these studies show benefits with radically different doses and sort of all over the map with the types of devices used, with lasers applying light to a few specific points, all the way to huge full-body devices or tanning bed-style setups with red and near-infrared lights that are irradiating the entire body all at once, and we’re receiving orders of magnitude different amounts of dose.
I’ve talked to a number of experts. I’ve read the literature, a lot of the literature myself, and I found that opinions on this are varied, so I’m very excited to dig into this with you. Before we get into specifics, is there any sort of broad–, like how would you describe the sort of broad issue with dosing when it comes to photobiomodulation?
Dr. Arany: Thank you for that question, Ari. I think that’s one of the major points of contention, and I think of them as an opportunity to move the field forward. You’ve mentioned already that there is so much discrepancy– Not discrepancy, I think the effectiveness of various treatments in different formats, which could be a single small point, spot size, to a very large array, to LEDs versus lasers, to different wavelengths of light, right? There are so many of these parameters which are different, but still seem to have a clinically therapeutic benefit.
The good news is, I think PBM has been very forgiving in terms of its efficacy, and I think the general consensus in the field is between 40% to 60% to 70% almost, depending on the application, we can actually get to that effective dose very easily and with different devices with different formats. However, I think the precision [crosstalk]–
Ari: Sorry. One quick question, Dr. Arany. You said something about 40% to 60%. Is that referring to the percentage of experts in the field as far as the consensus?
Dr. Arany: That is the success rate.
Ari: Okay.
Dr. Arany: Depending on the application from diseases like concussion and PTSD to wounds where we have some of the best data, or supportive cancer care such as mucositis, I think that number goes higher and higher because people have been using more rigor in terms of documenting where and how PBM has been working. Those have been, I think, areas where we are more confident that, within that range of parameters, which is how the World Association of Photobiomodulation actually has put out guidelines, it is not a single protocol.
It’s a range of parameters where we know that this treatment is effective, which includes different wavelengths or different colors of light, a range of energy that can be delivered in different footprints, like a single source that you are doing multiple spot treatments or like stamping, they call it a stamping technique, or some of them use a scanning technique versus very large arrays, which are basically the same energy but it’s in a static format and it’s given concurrently. I think we realize in the field, as you’re pointing out rightly, that both these formats, all of these formats actually work, but there must be a median point at which all of these should converge logically.
That’s where, I don’t know if you’re already familiar with this, but we’ve been thinking–, after we did the comprehensive review, not us alone, but I think a global group of experts looked at the supportive cancer care evidence, and they found that PBM works with different colors, different doses, different formats, LEDs and lasers, we were trying to come to a foundational concept that integrates a lot of this stuff.
Photon Fluence
That’s where the concept of photon fluence and Einstein came about. If you’d like, I can elaborate a little bit more about that.
Ari: Please, yes.
Dr. Arany: Photon fluence– Now, conventional PBM dosimetry is irradiance × time, which is milliwatts per centimeter square × seconds of treatment or minutes of treatment. The product of these two results in joules per centimeter square, which is, for all practical purpose, the dose that we care about so much. We know that within the irradiance and time, there is some reciprocity, and work from Dr. Hamblin, Dr. Anders, Jan Bjordal, and many of the pioneers of this field have shown that there is always some extent of reciprocity between the irradiance and time, which is the power density and time.
You can get to the same joules per centimeter square, but you can change it a little bit, not to extremes. Now, after looking at all the literature that I just told you about in supportive cancer care, it looks like we must also address the color of wavelength of light. Therefore, we have started to plug in the photon energy and have started noticing an improvement of our results. What I mean by that is a blue photon is like a watermelon. It’s a very, very energetic photon, a single blue photon, while a red photon is like a grapefruit or an orange. It’s smaller than a watermelon, but it still has a lot more energy than, let’s say, a 1064 or a 980 or a 940 photon, which is like a grape.
It’s like a really small photon energy, but we know that right now we do 3 joules per centimeter square or 6 joules, depending on whose protocol you’re following, and we don’t really pay attention to which wavelength, and we still see effects. Now, if we were able to add this photon energy and account for the difference, we start seeing an improvement in the consistency of the clinical results.
Ari: Explain what you mean by that.
Dr. Arany: It’s more easily visualized. What I mean by that is basically adjusting for a large photon energy like a blue versus infrared, which is really, really small, by compensating the irradiance or time, which is more effective. We can see that the same joules will actually make more sense.
Ari: You’re adjusting the dose down for a more energetic photon and the dose up for more getting into the infrared range?
Dr. Arany: As long as you don’t cross the thermal threshold, that’s the caveat.
Ari: Okay.
Dr. Arany: We know with infrared, you can easily heat tissues, and that is not what we want to do in PBM. As long as you pay attention to that, this compensation seems to help a lot. That is the concept of photon fluence. However, if we start talking photon fluence, we’ll all have different numbers because we all like different wavelengths. This is particularly relevant when you’re talking about very well-established PBM centers like Brazil or Paris, Europe, Asia, some places in Asia, or the US. All of us seem to have access and preference for a particular wavelength because we have more experience.
The photon fluence, unfortunately, would have become confusing. Therefore, to harmonize all of us and speak in the same language, we have decided to, as a field, agreed to use 3 joules per centimeter square at 810, which is 4.5 photon joules of photon fluence as 1 Einstein. That number helps us talk in the same language no matter where we are.
Ari: When did this agreement happen?
Dr. Arany: This is how the WALT Guidelines for Supportive Cancer Care is published. We had consensus among those experts because they reviewed the literature, and then we have agreed that this would be the most appropriate way to represent it. Only time will tell how accurate it is. Again, we are not trying to confuse people. There has always been a concern that new terminology will be confusing.
Ari: Yes.
Dr. Arany: However, if it moves us in the direction of harmonization, I think it will be a big win for the field. We’re already seeing a major difference, both in lab research as well as clinical studies.
Ari: Meaning the major difference that they’re seeing is they’re refining their doses to be more precise for a given wavelength and therefore dosing more accurately and getting a better result.
Dr. Arany: Right. I think this is very nicely illustrated. This is a podcast, so I assume that your viewers cannot see any visuals, but–
Ari: We can do a screen share. There’ll be people listening, but also people watching on YouTube. Let me open up Sharing so you can share your screen.
Dr. Arany: Yes, that would be ideal because I can show you what that means in terms of calculations.
Ari: Go ahead, and you should be able to share your screen now.
Dr. Arany: Just give me one second. I will pull up the slide. The idea there is that the same three joules, right now you will see most of our conventional protocols don’t talk about wavelength. They just talk about the dose, which is joules per centimeter square. That we find is not adequate information for people to do reproducible consistent treatment. Let me just show you this photo with so much new evidence coming in.
How different wavelengths penetrate tissue
Ari: Dr. Arany, I don’t want to throw a monkey wrench into this, but I feel like this is also further going to be complicated by the issue of penetration, given that blue light does not penetrate deeply, and 1064 or 810 do penetrate very deeply. You’re saying that with those, in the near-infrared or mid-infrared range, that it’s not enough of a dose, but if we’re looking at a particular depth of tissue, actually the only wavelengths that would even be delivered to that tissue at a particular depth below the superficial tissues would be the 810 and the 1064.
Dr. Arany: That is an excellent point, Ari. What we’re doing currently is using colors, or people who are doing PBM, are using the wavelengths as a mean to deliver different tissue depths. Because as you pointed out, the visible light will be attenuated right at the surface, while the infrared will go deeper. That’s what’s shown pictorially here. You have the superficial– This should be a little bit more superficial, but this is more deeper, but what people are doing now is combining two wavelengths so they can treat larger volumes of tissue.
The future of PBM is definitely multi-wavelength light, and people are combining wavelength, visible and near-infrared, to try and treat larger volumes of tissue. Currently, we only say 3 joules and we don’t truly differentiate between the depth of the tissue and the volume of the tissue, right? We just say 3 joules at 660 and 3 joules at 810. What this new paradigm allows us to do is add those two energies so we can truly precisely point out how much energy is superficial in both the wavelengths and how much energy is actually going deeper.
This is what radiation oncologists do when they’re talking about dosimetry to hit a tumor which is deep-seated. They don’t hit it with a single beam. They actually use many, many, many fractionated beams and try to address. We talked a little bit about this last time. You can get to a deeper tissue by using multiple beams, right? That is what most people are trying to do when they’re combining wavelength. However, they have not accounted for that energy that is actually common in the superficial layers from both wavelengths. With this new concept, you basically account for individual photon energy, and when you add those two, you get the cumulative energy.
Ari: Wow. Okay. I’m overflowing with questions here. I almost don’t even know where to go, but I feel like there’s many layers that we have to explore to get into this. One thing that I want to say is I feel like this is a big breakthrough for researchers and for the field as a whole, but I feel like it’s also something that is going to overwhelm and sort of profoundly complicate the practical side from consumers’ perspectives, “Well, I have this device, I’ve got this LED panel. Now, I have no idea what the proper dosing is.” Right?
Dr. Arany: I hope by the end of this section, you can actually– We thought of that, and we have given a cheat sheet, if you will, to try and convert these doses a little more precisely. Let me come to that. This is your conventional dosing, right? Fluence is irradiance × time. However, if you start adding the photon energy, which is, let’s say, blue, red, and infrared, you very quickly see that the 3 joules at the different wavelength actually are different photon fluence values, because you added different amounts of electronvolts for each– different type of photon.
This is how we are doing current treatments in PBM and even a layperson can tell you that 8.1 is very different than 4.9. It’s almost half that, right? It’s actually less than half that. This is why we are not seeing consistency between protocols because people are doing different things and some people see better results, some people don’t see results. Again, with the caveat that PBM works in a very broad range but has not been very consistent because we have not been paying attention to this.
All we need to do, as I pointed out in the earlier part of this talk, is basically divide this number by 4.5, the photon fluence by 4.5, and now we are talking in the same language. Everybody is in Einstein, irrespective of which wavelength you’re using and the energy that you’re actually depositing, so all of us will be talking in the same language. As you pointed out, this is a lot of math for a clinician and a biologist, so we made this cheat sheet, which basically talks about, we know that the photon has a very, very complex energy transfer process once it’s inside the tissue.
We are recommending, and everyone practically can do this, is measure or calculate the amount of energy on the surface, irrespective of the wavelength, which is called the tissue surface irradiance. Then you plug that number into this to get the photon fluence, and then you get the Einstein. If you’re using more than one wavelength, you will get multiple photon fluence, which you basically add together, and you will get a cumulative number. If you don’t want to bother about all of this, which I think is more research, as you’re correctly pointing out, you can look at this adjustment number here simply.
If you have a dosage at 810, you need to do this percentage less treatment, either in terms of irradiance or in terms of time. We find time is an easier constant to adjust. If you’re using a red, you need 30% less. If you’re using blue, you need 80% less. We know that this concept works because we have done all these research studies to actually do all permutation/combinations.
Difference in treatment time and dose
Ari: Okay. Now, more layers that we need to go through. One of the biggest ones, and I want to throw another monkey wrench into this, is, if you go back to actually the chart that you just showed there, it’s saying, “We’re standardizing for 810 nanometers.” That’s where the standard dose is that we’re targeting. Then we’re creating adjustments from there, depending on whether you’re using less nanometers, you’re using, let’s say, in the 600s, or you’re using in the higher 800s or 1060 or something like that. We’re adjusting the dose to account for that in either direction, either higher or lower. However, all of that presumes that there is some kind of a standard dose that is agreed upon that we’re targeting.
In my experience, I’m sure you must have an answer to this. You’ll be the first that I would encounter, but the dosing from the actual studies is all over the map. There doesn’t appear to be a consensus. I mean, what you’re implying suggests that there is, but I have not seen any sort of consensus in the actual research of, okay, at 810 nanometers, these are clearly the proper dosing parameters. You can find a study on, let’s say, periodontal health or treating muscles after exercise to enhance athletic recovery from exercise, where they’re using an order of magnitude dose different.
I mean, not just small variations of dose, but massive variations in the dose. I’ve spoken to Michael Hamblin about this issue, and he is pretty loose with his ideas around dosing, and he’s sort of the opinion that it’s really hard to overdo the dose and sort of more is better, generally speaking. He’s not– And this is getting into another issue that it sounds like you must have a different opinion on, which is the biphasic dose response issue. I think Dr. Hamblin is much more concerned about underdoing the dose than he is about overdoing it. I think that’s fair to say. How do you want to start unpacking some of these layers that I’ve asked there?
Dr. Arany: Yes. There are multiple things we can talk about, and Ari, I think this is a many-part discussion in many ways,-
Ari: Yes.
Dr. Arany: -but let’s try to keep it succinct in terms of the specific points you made. First one, “Why do we have a different dose for different treatments?” Is simply because the target is different. When I say target, I mean at the macroscopic level we are talking about different cell types. One quick example, if I may show you. I trained partly with Dr. Hamblin. With all due respect, I will disagree on the overdosing versus the underdosing aspect, but here’s some experimental value that you can actually see. Can you see my slide?
Ari: Yes.
Dr. Arany: When you do light treatments on any part of your body, you’re going through multiple layers of different cell types, like the epithelium, the underlying connective tissue, which has blood vessels, it has inflammatory cells. This is an example, and this is already published, so you can see the publication reference here. My group was very interested in how is it that when you’re doing wound healing treatments, we have to use different doses for different responses. Simply put, the epithelial cell, which is the most superficial layer, which is naturally exposed to light, is much more sensitive to light compared to the underlying fibroblast.
How can one cell interpret the light energy in a different way turns out to be a feature or a characteristic response of that cell type. A fibroblast is much more resistant to light energy because it has higher levels of ROS scavengers such as catalase. In this publication, we showed that fibroblasts actually need a much higher dose to respond compared to a keratinocyte, which is much more sensitive. If you take the– You remember, we talked about wound healing a lot last time, and that remains our most important prototypical biological system.
When we look at wound healing, you have epithelium or the surface layer crawling, you have the underlying connective tissue that has to form, which has blood vessels and inflammation. We asked the question, do we need different doses at different points in that healing response? Surely enough, as you can suspect, we need a higher dose for the fibroblast to make collagen and induce that closure of the wound compared to a lower dose for the epithelium to crawl over.
This is a simple example in a single disease, if you will, or a process where you need different doses for different cell types. Now, if you make this even more complicated and say, let’s do diabetic wounds, let’s do infected wounds, let’s do pressure wounds, then we are realizing that we need different doses even within that spectrum. If you extend this to a larger part and say, wound in the mouth versus wound in your feet versus wound inside your abdomen, again, it is very logical that these cells are exposed to different kinds of light, right?
Very little in the abdomen compared to on the skin, very much more on the face and your limbs than your abdomen or back or your neck, right? All of these are playing very important roles in precisely defining the right therapeutic dose. We are capable of that kind of precision. One of the good news in the field of PBM is that we are getting to that level of precision, but unfortunately, the bad news is that we’ve been using a single dose and trying to fit all the responses within that. You can also ask that question, if wound healing has so many different doses, Parkinson’s, Alzheimer’s, tendonitis, obviously will have very, very different doses.
This is the first part, hopefully, that points out that we should be exploring different doses for different applications. We are getting there in many, many areas, at least on the research front. I think it will take more time for the clinicians to catch up– clinical research to catch up. The other part is the Arndt-Schultz curve, but I’ll let you weigh in on this one before we move on to that.
Ari: Yes, I’m overflowing with questions here. The way you’re speaking about this implies that there are very precise doses. I certainly don’t want to put words in your mouth because I don’t think this is what you mean, but it almost implies that getting the dose right is so important that the difference between this dose and this other dose that’s pretty similar, let’s say it’s within 30%, plus or minus 30%, of this optimal dose is a bad dose or is going to be ineffective or is going to be harmful.
I think that can’t be true, given that the body of research uses so many different doses with different devices, and yet they’re all showing– Not all, but a large majority of studies on a given benefit, let’s say, use the example of muscle recovery after exercise. Different devices applied in different ways with radically different doses still show a positive effect.
Dr. Arany: Right. That’s a great segue into the Arndt-Schulz curve. The Arndt-Schulz curve, for the listeners who are not familiar with the concept, is the effect where you see a stimulation or inhibition that is therapeutic in the beginning, but if you continue to dose, you start seeing the opposite response and you start seeing a loss of therapeutic benefit. That is the classic Arndt-Schulz curve that people describe.
Here’s an example of many precise biochemical and molecular assays that we do, where it is easier to define and visualize what that Arndt-Schulz curve looks like. Like you’ll see a lot of clinical evidence where there is a precise amount of stimulation, and then after some time, you can see that it actually starts inhibiting it.
Ari: Dr. Arany, let me just interrupt briefly to explain to listeners. This is referring to, it’s sometimes referred to a biphasic dose-response curve. It’s also the Arndt-Schulz curve, named after the researchers who sort of, I don’t know if they discovered it or they were the main ones putting this idea forth, or it’s also talked about frequently in the context of hormesis and hormetic stress, where basically a low dose will not be enough to create an effect. You need to have a significant enough dose to create the effect, but if you keep going and you overdo it from there, you will actually inhibit the effect, you’ll cancel it out, or maybe even create a negative effect.
This principle applies to many different things like exercise, for example. If you do a very small dose, you probably won’t get much benefit. You’ve got to be in the right range of dosing to get that effect. If you massively overdo that, exercise becomes mostly harmful. Just for listeners, I wanted to give them some context to understand what you’re
talking about here.
Dr. Arany: Perfect. That’s a good segue. Again, that’s a good continuation of our discussion about too little or too much dosing. Too little dosing, I think is very intuitive for all the listeners, that if you don’t put enough energy, light energy, into the system, you will not see a response. However, when you reach that precise therapeutic threshold, which is usually this part of the curve, if you’re looking at the graphs here, you know that you’re going to get an optimal response. Now, the optimal response can be either inhibitory or stimulatory.
It can be either reducing pain or inflammation or stimulating healing. However, when you increase, further increase the dose, you start negating those benefits. It does not reverse the effect, but it actually causes the loss of that effect. Now, you can imagine that as soon as you start seeing a therapeutic benefit all the way till you start losing all your benefits is a very large range.
That is the other reason that photobiomodulation has been persistent and has been around since the ’60s, is because people have seen the benefit, everything like we said, between 40% to 60% all the way up to 80%, depending on the application and the expertise of the operator, the clinician who’s giving the dose.
Ari: Just for listeners, I want to translate this. Any different type of stressor potentially has a range where it’s beneficial. We can conceptualize that as sort of a broad range where pretty different doses can still be beneficial, or a very narrow range, very tight range, where if you slightly overdo the dose, you’re going to very easily go into the territory where it becomes harmful.
There’s animal experiments, for example, involving radioactive materials or even exposure to heavy metals like mercury or arsenic, where they can show a beneficial effect on lifespan, for example, in flies or maybe in rodents or something like that, but if you happen to slightly overdo that dose, you’re going to very easily enter the territory where those things become much more harmful than they are beneficial. Whereas something like exercise, for example, there’s a much broader range of dosing where you’re going to be in the beneficial range rather than the harmful range. It’s really hard to overdo it. It’s possible, but it’s really hard. It takes a lot of effort and a lot of time to massively overdo exercise to the point where it’s harmful to your health.
Dr. Arany: I think a good analogy to that, again, is sports people, athletes, right?
Ari: Yes.
Dr. Arany: They are actually really, really, really good at what they do in the activity that they do, but they can get hurt if they overdo it. Which is why a rest phase is usually an inherent part of their training. It is not an option to rest between tournament days and your activities. That’s a great analogy. I think any stressor can be beneficial within a long range but can potentially cause harm.
The biphasic dose response in PBM
Ari: Yes. Okay, so biphasic dose response. Let’s go deeper into this because I’ve seen very different opinions on this. Michael Hamblin’s position, again, I don’t want to– I’ve had a lot of back and forth with him on this because I find his position maybe a little bit shocking, but his position is essentially, he’s not really that concerned about it. He says this biphasic dose response really shows up more in vitro experiments on cell cultures in a Petri dish and that sort of thing or in animal experiments, but that he does not see strong evidence for it in the in vivo human data. What do you think of that?
Dr. Arany: Again, with all due respect, he is one of my mentors and of course, a pioneer in the field. I disagree. I think what we are seeing is not inhibition or loss of therapeutic benefit. We are seeing reduced efficacy and inconsistency in PBM clinical responses. Again, and having done several clinical studies ourselves, I have seen this in my own personal experience, but I think every person who’s actually doing PBM treatments, one of the frustrations of doing this treatment is we might do the best treatment we know how to do, but we are not seeing that reproducibility that we would like to, to the same extent that we would get with other therapeutic modalities.
That is something that I feel is one of the, after you talk about target differences in dosing, it is the second of the three major problems with PBM dosimetry, which is overdosing, because as clinicians, we are motivated to give them maximal benefit. As patients, you are motivated to get maximal benefit without repeated appointments. Unfortunately, that doesn’t work in this treatment. You have to be patient and you have to do multiple repetitions in some cases to actually get maximal benefit. It’s very subtle.
That’s the other thing that people find. A practical joke that several of my colleagues tell me is that neither the patient feels anything nor can the clinician see any change, but we still charge them money. That is one of the problems with this treatment, is people stop–, they’re not patient enough to see the benefits after two to three appointments.
Ari: Yes, there’s an interesting thing. I mean, here’s a lot to say on that, but even something like exercise or meditation is like that. We could look at healthy foods like eating broccoli or blueberries or something like that. We have robust data showing that consumption of cruciferous vegetables or consumption of darkly colored fruits is brain-protective and protects against cardiovascular disease and protects against cancer and things like that, and yet somebody could eat any of those foods every day for a week and not notice anything, right?
We have a broad category, I would say a huge range of different strategies that relate to health and disease prevention and longevity, that we can’t necessarily immediately perceive an effect from. Because humans are so oriented towards immediate gratification and because if we can’t subjectively notice an effect relatively immediately, we’re inclined to believe that something doesn’t work. I feel like that creates a sort of a big problem with a lot of strategies related to health, including red light therapy.
Dr. Arany: Absolutely spot on. I think the conventional way of treating, either surgery or popping a pill, is instant gratification, right? You can see and you can experience the intervention. Unlike light, because most people will– Some people notice nothing. Some people just notice a slight warming of the tissues that is being treated when you’re doing PBM accurately.
You should never feel uncomfortable or hot when you’re doing PBM, even in the beds and the large panels. That’s again, going back to the overdosing problem that we are seeing in the field. You’re absolutely spot on. I think that instant gratification, unfortunately, is the current mode of health and wellness. People just have to be just with exercise and diet. It is not an instant thing. You’ll have to work on it to get the benefit.
LED panels or laser devices?
Ari: Yes. Okay, so I have a big question for you. I’m a little bit scared of your answer here. It is, the way you’re talking about the dosing is it almost creates a bit of a concern like, well, are all these people who have devices at home, who have LED panels or pads or other styles of devices, are they potentially getting dosing radically wrong? Or do you think that the dosing range where it’s still going to be a mostly beneficial effect is so big that even with our enormous lack of precision in dosing parameters for these different devices, we’re still mostly in the beneficial range?
Dr. Arany: I think more of the latter, Ari, fortunately for us, and again, we don’t have hard data to back this up, but we point to the fact that this treatment has been around since the late ’60s. If it was truly voodoo and pseudoscience, it would have disappeared by now. The fact that right now you can go on Amazon and Alibaba and order more than 100,000 units of different formats, sizes, colors, a lot of which, unfortunately, are not very reliable. The fact that you can do that points to the fact that it is very forgiving. The dose range, as Dr. Hamblin also correctly points out, is very, very forgiving.
Ari: Okay, that’s good news. Do you have any guidance for people, let’s say, who have LED panels at home? Let’s say they’re a mix of wavelengths in the 600s and the 800s. What do you think is a range of optimal dosing, and let’s say the irradiance, I have a lot of third-party lab data on some of these devices, so I know the true numbers, not the ones that the companies give on their websites, which are very inaccurate, as I’m sure you know.
Let’s say we’re in the 60s or 70s as far as irradiance milliwatts per square centimeter. What does treatment time typically look like? I don’t know if you want to differentiate between superficial treatments, like for skin, anti-aging effects, or wound healing in superficial tissues versus trying to treat deeper tissues.
Dr. Arany: Again, as we discussed previously, each disease and its anatomical manifestation has, we believe, a specific dose. At the moment, you will see that we are putting out guidelines in a range of possibilities, but we are trying to distinguish like pain in the mouth versus pain in the knee and pain in the neck. They are very different anatomical sites, even though the disease process is still pain. Pain itself can be neuropathic, it can be inflammatory, it can be different types.
The good news is PBM is moving towards precision medicine. The, unfortunately, bad news right now is we don’t have all of it figured out yet. Having said that, I think we are making– I think medicine in general is moving in the direction of personalized, optimized care. The opportunity with light and PBM is that we are very, very aligned with that. Actually, we have a tool which can do this in a much, much more precise manner than any pill or any surgical device.
Ari: What’s that?
Dr. Arany: Sorry?
Ari: What is that that you’re referring to?
Dr. Arany: The optimized, personalized care for each patient.
Ari: Okay, but what’s the tool that you’re referring to?
Dr. Arany: There are different tools and different parameters that can be optimized for a patient. Let’s go back to the example of pain. Pain in your mouth versus pain in your neck versus pain in your foot has to be treated within the range of the pain PBM protocol, but has to be tweaked depending on what you’re trying to treat and what area you’re trying to treat. Which is the third point. I told you that there are three dosing aspects that we are very, very passionate about and inquisitive about. One is obviously the photon energy and the target, which we talked about in detail from where the photon fluence and Einstein came about.
The second one, again, very relevantly is the over-treating on the Arndt-Schulz curve, which we have noticed is the reason for inconsistency because you’re neutralizing your benefit. The third one, which I think we kind of touched on before and even are talking today, is the format of treatment. If you have a fixed format, which is like a panel or a beam, which is fixed, it makes life easier in terms of research because we can tell you the precise dose, but you know and every practitioner that I’ve worked with knows, we don’t do that.
We actually use scanning motions and scanner motions and stuff. There are several groups that are looking at very sophisticated robotics to try and do this in a very precise manner, and so are we in our research group. The delivery of that dose is a huge new variable space that people are trying to optimize. That I think is the third wheel that will actually make dosing very, very, very precise, optimized and personalized.
Ari: Can I sort of play devil’s advocate and push back a little bit on the paradigm that you’re presenting around dosing?
Dr. Arany: Yes.
Ari: I’m imagining someone making similar arguments when it comes to exercising in a gym. I have no doubt that you could, let’s say if you took 100 random people and you did testing on them and their responses to a given amount of exercise, a given intensity of exercise and so on, you would find very significant differences in those individuals’ responses to a given type of exercise or to a given dose of a workout, a 30-minute workout at X intensity. For some people, it would be way too much. For some people, it would be just fine. For other people, it would be very easy because they’re actually much fitter than that and so on.
Even going down to the nuance of a single exercise, let’s say doing a bodyweight squat all the way down. Some people, their joints are not even mobile enough to get in that position or they don’t have the strength to do a single bodyweight squat. For another person who is used to squatting 300 or 400 pounds, a bodyweight squat is nothing. We could find lots of individual differences in that. Out of that, we could then say, well, we’re identifying the precise dose and it’s very important that everybody gets their precise dose to get the benefit.
To an extent, that’s certainly true and yet at the same time, if we’re trying to sort of educate the masses on the importance of doing exercise, we wouldn’t want to overwhelm them by making them think that getting the absolute most precise dose when you go to the gym and do exercise is important. It’s the make or break factor, the difference between getting any benefit or no benefit at all. Unless you get that, you know the exact/precise benefit and the exact types of exercise and the exact intensity that you need, you need to avoid exercise because it’s very important to know all those details.
I would definitely argue in favor of like, “Hey, we need to not overwhelm people with all those details. We need to have the message of using exercise and then experimenting and finding the dosing range that works for you and the type of workouts that work for you, depending on where you’re at.” You get what I’m arguing here?
Dr. Arany: I get it, and I’ve actually spoken to many sports medicine specialists. I actually work with several of them who have made that argument. My response to that, and I have put some thought into this, so you will see that. Let’s take that example of the squats. Ideally, we would be thinking about larger weights and longer repetitions, right? That would be ideal in terms of building body mass and building resilience in the client, if you will.
If we focus only on the weights and the repetitions, it is going to be very different, as you’re correctly pointing out, for a small-build person versus a large-build person, males versus females, different racial differences. We are not ever going to optimize it by focusing on the weights and the repetitions. However, if we start measuring the change that a single rep or a single amount of weight does on the patient, on the client in this case, we have something to measure the response. Let’s take a–, and I’m saying this because we are doing this with another collaborator here.
Ari: Even without even measuring the response, in the case of exercise, you can ask somebody to pick up a given weight and you’re going to see immediately whether they’re strong enough to do it or not.
Dr. Arany: Right, but if you can measure a change that is induced in the person, then you can tune the prescription and give them an exercise prescription. Given the technology and the advances we are making, measuring heart rate 24/7 now is not trivial. It’s not difficult, it’s actually pretty trivial, right? The group that I actually work with uses heart rate variability. Another group that I work with uses blood pressure and respiratory rate. Simple physiological measures, nothing sophisticated like EEG and electromechanics.
Ari: You’re saying they use those metrics to determine the physiological response to photobiomodulation?
Dr. Arany: No, not yet photobiomodulation, but they’re using it to, like for a treadmill test or for weight squats like you’re measuring, right?
Ari: Right.
Dr. Arany: They have them do an activity which they are comfortable doing and trained to do. Then they measure these simple physiological variables. Then they can actually write a prescription based on some change in the person. This is the direction that PBM has to go in and is going in, at least at the clinical research front. It is still not something that’s available, but that is the direction that the field is going towards, where you’re not so much worried about the variables because we can easily change the variables. I mean, device variables, dose variables, and delivery variables. What we should be paying more attention to is the patient response or the client response.
Ari: Yes. That information, like I’m thinking in the context of exercise science, which I know very well, certainly will give you valuable data, but it’s far from the the be-all, end-all. You could measure lots of– You could measure HRV, you could measure the amount of subjective soreness or energy levels of that person just by a simple questionnaire. You could measure heart rate. You could measure blood markers. Actually, all of those have fairly limited ability to really accurately predict whether or not somebody should do another workout.
I mean, they have some predictive ability. They do give us some indication, but they’re far from perfect indicators of, the way that an exercise scientist would train an athlete involves some degree of tracking sort of these metrics and modifying training accordingly. “Okay, you’re clearly very fatigued today. Your HRV is lower. We’re going to do a lighter day today in terms of the intensity, but for the most part, we have a plan that includes dosing and hitting certain goals of the training, and we’re going to follow this plan.” You know what I mean?
Dr. Arany: Right, and I think what has– I agree with you. I agree that a single measure is usually not very predictive. Now, the power of AI, and wearable sensors specifically, has brought multi-attributes into something that can be in real time, in high-throughput data format be analyzed very, very quickly. That, I think, is where the field is going.
It’s never going to be a single measure, but a composite of multiple measures, which will actually feed into, a predictable or what’s changing in a predictable manner. That is something that we feel, and we have lots of research evidence, that this is what will actually move the field forward. You can tune many variables and delivery system, curved panels, beds, multifractionated beams. You can do all of that stuff, but what are you trying to change if you’re not measuring the host? Then we are not completing that picture.
Ari: Okay. Just trying to paint the practical picture of what this looks like. Again, using exercise as an example, let’s say we had a given target for our workout. Let’s say one group of people used metrics to track their responses to workouts and adjusted the dose of their exercise accordingly. As the example I gave, “Okay, heart rate variability is lower today, or you’re feeling fatigued or you’re feeling very sore, let’s do a lighter day as opposed to, let’s adjust the dose or intensity of this planned workout down by 20% or 30% or 40% or 50% compared to what’s planned.”
I had another group where they didn’t do any tracking of metrics to optimize their dose, but they just followed a piece of paper, basically a workout plan with specific workouts of what they should do, whether they felt good or whether their heart rate variability was a particular thing, they just followed that plan with no tracking of metrics. I would imagine for most people outside of elite athletes who are on the edge of overtraining and where that biofeedback becomes extremely important, but for the average person, you’re talking about something that’s maybe less than 10% of the overall picture of the benefits of that activity.
I mean, it’s an excessive amount of focus on a factor that’s really a minor factor in their overall results, but you think in the context of photobiomodulation, it’s going to be a much more important and much bigger variable?
Dr. Arany: If you start thinking of light as a supplement, which we talked about last time, or light as a drug, which is basically an expansion of that same concept. If you start thinking about that in terms of active way of modulating your activity, we all have our baselines, right? All of us would love to exercise more, eat the perfect diet, but it’s not very practical. I think the change, and especially if we–, and I think it’s going to happen one way or the other, either with these wearable watches or other bands and clothing now, which have sensors in them.
I think it’s a matter of time before all of us have our digital baselines in some manner registered. When we change from that baseline, it’s never going to be perfect for all of us. It’s going to be very, very different for everyone, depending on what they’re doing and what kind of activity they’re pursuing and what kind of work they do and what kind of life they live, right? All of that will define our–, and we don’t think of it as a straight line. We think of it as a, I actually have an image somewhere where we show these minor variations, some major ones, but mostly minor variations.
Idea is that, if we were to have some kind of a disease state or a lack of our wellness state, any deviations from that, the idea would be to get us back to that minimal deviation. It is not to get us to some kind of an ideal plan for everyone. That’s not going to happen. That is only possible if we start measuring people rather than just giving everyone the same thing.
Optimizing red light therapy
Ari: Okay, so how do we bridge this gap between what you’re describing as sort of the ideal world of having very precise metrics to track responses, very precise ways of dosing at particular wavelengths with particular kinds of devices applied in particular kinds of ways. I understand there’s an ideal there, and yet we have this sort of practical reality that we’re living in now, which is red light therapy, near-infrared light therapy, photobiomodulation has exploded in popularity.
We have millions of people who have devices, who have LED panels, who have pad-style devices, who have face masks, things like that, who are listening to this podcast and saying, “Just tell me how do I optimize my dosing?” What would you say to those people? How do we bridge the gap between the ideal and what’s–, like giving some practical guidance?
Dr. Arany: The good news is this treatment works in a large range of parameters and in large formats that are available already. Many of it is just freely available. There are some good companies that make rigorous devices, which we would strongly recommend. The World Association is trying to partner with many of them to try and not certify it but ensure that those devices are reliable, because that’s what we owe to our customers and our consumers. It is still a few years away, but I think it will happen. Eventually it will happen.
Having said that, I think all of us would like personalized care if we had the option. Not many of us do, right? If you were given the option of going to a spa versus treating yourself with an infrared lamp, all of us would prefer going to a spa where someone is taking care of everything and we’re just taking care of ourselves, right? That, I think, is where we are with the field. I feel PBM will go forward in two major directions.
One, we will go towards very precise, optimized, personalized PBM clinical care, which will usually be, I think, lasers and many, many very sensitive and sophisticated sensors. Think of them as MRI on steroids. I think that’s where we are going to go with many of these sensing. There are very, very elegant spectroscopic techniques and other imaging techniques that can give us very, very precise information. That will be one direction the field will go, and you will probably get this kind of care, hopefully in an affordable manner, but you’ll get this kind of care in a clinical scenario or a medical spa scenario. The other end of the spectrum is the devices themselves that are available for at-home use will get better.
The simplest way I think they’ll get better is they will actually deliver the specifications, like you’re pointing out, not all of them are actually delivering the specifications they’re sold with. The simplest thing is when people–, and I don’t think manufacturers are bad guys, they just don’t know. They just make a red color without paying attention to 630 versus 660 versus whatever in between. If they are told like this is the ideal one, I think they’ll make it. That’s not a difficult information to get.
Right now, as you pointed out, it’s everywhere. The numbers are everywhere. Everything from irradiance to CW versus pulsed, to the actual color. Red is a spectrum of colors. Even one wavelength, we have no consistency. I think at-home use devices will get better and more consistent, but they will not replace, I think, clinical treatments. I think those are two separate worlds. Connected part of that is who is going to give these treatments. If it is safe and easy enough to use at home, it should be everybody in the clinic.
However, if you start thinking about the most sophisticated lasers and those systems, I think those would be largely relegated to trained personnel, clinical personnel. Not necessarily a physician. It could be a physician assistant, it could be a special technician, just like they have radiation technicians who do the actual radiation treatments.
Ari: Is there any sort of piece of advice or guidelines that you would offer to people with some of these home devices? Let’s say they have an LED panel that’s in the range of 60 to 80 milliwatts per square centimeter, and they’re looking for overall systemic benefits, skin anti-aging, systemic anti-inflammatory benefits, and maybe they want to sort of affect muscle recovery or affect joint health, and they have arthritis and they’re trying to increase healing in damaged tissues and so on.
What do you think, extrapolating– I know that you have a lot of resistance to this, but going away from the realm of extraordinarily precise dosing for all kinds of specific purposes, if we’re speaking to the average consumer who has one of these devices at home, what guidelines, practical guidelines, would you offer them?
Dr. Arany: Use the device in a safe manner, which is, it doesn’t make you uncomfortable either through heating or through very bright light in your eyes. Use the device in a safe manner is my simplest recommendation. Hopefully, you’re buying it from a reliable manufacturer. A lot of us, when we go online shopping, are looking for the best deal. Unfortunately, that doesn’t always get you the best device.
One good way of looking for that is if you see published scientific papers with the device, it usually will show you that they are reliable enough for that kind of work. Many companies will post publications and scientific papers, but they are just randomly in the field for red light or infrared light, not with their own device. I would say for a descreening customer to look for devices that have been used in clinical research studies, not just the color or generic wavelength but their specific device.
That would be my recommendation to your customers who are using it already. Choose a reliable device and don’t just go buy papers published in that field that they put on their website. Have they used that device in a study would be very helpful. One other way of looking for a reliable manufacturer is to see who participates in the field. Were you at the London meeting?
Ari: I wasn’t, no, but I saw some of the presentations from it.
Dr. Arany: Right, a meeting like that where we know that PBM experts are going to be there, Dr. Hamblin was there, Dr. Anders was there, Dr. [unintelligible 01:01:07], pretty much who’s who was there in the PBM field. Meetings like that where you know people who are publishing well in that field, you can see who participates. A lot of companies, this time we had a bonus crop of exhibitors and some of the best companies that we are familiar with were there. Some of the companies were not, but most of the companies that we are familiar with actually turned up.
That’s another good sign. They are not afraid of showing their devices and getting feedback from the experts in the field. That would be a good place to start looking, who exhibits at our main meetings, main photo biomodulation meetings.
Ari: Do you have any major concerns where there’s a specific area where you feel people at home with some of these devices are commonly using them in a way that you believe is dangerous or harmful or is not beneficial?
Dr. Arany: I’m not a big fan of lasers for home use. I feel that technology has a lower threshold of safety and a higher threshold for damage, however way you think about that. Even though I believe there are several laser diode devices available, I’m not a big fan of them being at home used. Even if they are prescribed by a clinician, then it’s a bit better, but that trend is catching on. Simply because it’s very difficult sometimes, when you think of a cancer patient or a chronic wound patient, they need to get treatments more regularly than they can visit a clinic, even if it’s next door. There are places where I think those devices are helpful, but on a large basis, prefer LED that are home use compared to a laser.
Ari: Do you have any reservations about LED panels, the large panels?
Dr. Arany: I feel a lot of them are unfortunately overdosing or are being used inappropriately where it’s causing overdosing. I know some of my friends who have borrowed my light panels and they are 2 health piece or 10 should be better, but that’s not the way this treatment works.
Ari: Say that again.
Dr. Arany: A lot of people who have borrowed our light panels for treating themselves, I tell them very precisely, “This is the amount you should be treating.” They say, “Let me do a little bit more. I don’t have time to go–” They will overdose it. I think that’s, unfortunately, a common practice.
Ari: Do you think the use of the LED style panels from 6 inches, 12 inches, 18 inches away, or a couple of feet away is generally beneficial to health or do you have any reservations or doubts about that?
Dr. Arany: I have reservations, but I have no doubt that it is helpful. I have reservations on, like I said, the manner of use. I’ve used one. I have two panels sitting right next to my desk and I use them throughout COVID and partly because of that and partly because we are so isolated, I think I didn’t get COVID, but I think the light definitely helped. Because maybe I’m just biased because of what I know, but I used it throughout my COVID years and had absolutely no issues. I think there is a place for LED panels during meditation, which is a really good thing by itself, but any specific activity in a controlled manner. It’s not always keep it on or keep it on for too long. That’s not advisable.
Ari: How do you use yours?
Dr. Arany: I follow the prescription and prescription in the sense of the presets that are available, but then I have learned that with experience using it many times, I’ve learned that how much dose is right for me. Obviously, I have a darker skin. Clearly, I’m more efficient at absorbing this light than a paler Caucasian person. A simple thing like that has helped me dose better. We have seen this in mice as well. We have done some very careful measurements and we have seen that the target is as important as your device parameters.
Ari: You’re somewhere roughly 10, 20-minute treatment somewhere in there?
Dr. Arany: Actually less, we don’t usually go that long. I think the manufacturers prescribe that number. Again, depending on whether you’re a big person, small person, there are some very interesting differences between males and females that’s coming out. I think it’s still a little premature to comment specifically about that but we are seeing differences.
Ari: How far away do you think is optimal to use a panel-style device? Do you use it from one foot away or do you apply it to the skin? I know Dr. Hamblin, I’ve had some discussions with him, contact versus non-contact, also discussions, one other area I’m curious what your thoughts are as far as the EMF issue, but how do you like to use your panels?
Dr. Arany: Ideally, we would use it in contact, but having said that, because we can very precisely define the dose, so it’s easy to do calculations and stuff. The more studies we do, especially clinical research studies that we do, we have started to realize that is not very practical. If you’re thinking about like we do, we did a concussion study and people have different kinds of hairstyles and stuff. It’s not very practical to actually place that probe in contact precisely in the same manner we did in the previous session. In the session, you can be precise, but when they come back for the next section, you’re not going to be exactly that precise.
We find that it’s much easier to be in non-contact and the loss that people are worried about in terms of reflection or whatever distance that you’re accounting for is very minimal. You can easily account for that by increasing the amount or time, which seems to help a lot. I’m open to both, and I think the contact is more precise, but I’m leaning towards a non-contact. This becomes a practical thing when you’re thinking of clinical care, because if you’re in contact, you have to disinfect that surface pretty rigorously. If you’re not in contact–
Ari: You’re using it on multiple different people.
Dr. Arany: A clinician would. A clinician, obviously, will go through many different treatments. I think that’s one of the problems with the bed. It’s not the treatment itself, but I think people are spending a lot of time actually cleaning the bed between patients. Again, I’m sure you’ve seen this already, but we have been a big proponent of half a bed. We just use that for–
Ari: Half a bed?
Dr. Arany: Yes. It’s just a half a panel. You can actually treat the person sitting comfortably rather than lying down inside. It’s not very easy to get in and out of that bed. Not for athletes, obviously, but if you’re thinking about frail, older people, it’s not very easy getting into those beds and coming out of that bed. We have been a big proponent of having the person sit comfortably and have that panel close enough but not blind them in any way.
Ari: Let me ask you about pad-style devices. What do you think of those? I’m sure you’ve seen the flexible neoprene pads oftentimes with LEDs spaced maybe 1 inch apart. I know they tend to be much lower power than LED panels. What do you think of those devices?
Dr. Arany: My gut feeling is that they are achieving that contact in the most precise manner because they’re soft and cushioned and very reasonable in terms of pricing. I think they have a place in at-home PBM devices. If they are personal use, I think disinfection becomes less of a concern, which is also good. If you’re going to be sharing that, then I would be concerned about the disinfection. Those are not easy to sterilize. Neoprene stuff is going to pull back some moisture and potential surface contaminants. If you’re talking about personal use devices, I’m fine with that. I think that there’s a place for that. I’m not a big fan of that in a clinical setting or a delivery setting.
Ari: Do you think the irradiance on the power density is high enough to create depth of penetration and a significant effect in anything other– This is, I guess, maybe getting at the next question, which is systemic versus local effects. Do you think that they’re getting significant penetration or would they mostly be hitting superficial tissues and irradiating the blood and you’re getting sort of a systemic benefit from that?
Dr. Arany: I think there is definitely systemic benefit. There’s no question in my mind that might be. We did a study, I don’t know if you have seen this one, but we tried to treat long COVID patients with brain fog with a helmet versus the bed. Our scientific rationale was that the helmet will work better because they have brain fog, and we were doing quantitative EEG, we were doing all kinds of questionnaires and stuff. Both of them, if you adjust the light treatment dose effectively, actually showed equal benefit, indicating that the systemic effect is as important, if not more important than the local treatment.
There are some really fascinating studies for Parkinson’s where, again, this may be a little too geeky for you, but this is like, they take animals, they inject a toxin, and they create tremors in the animal. When they treat the head, the animal gets better. This is John Mitrofanis and Oliver Stone’s work. Liebert is also a part of that team. These guys are very good at focusing their PBM research on Parkinson’s patients.
When they did the same experiment by covering the head with silver foil and just treated the body of the animals, the animals still got better, indicating that the precise location may not be the critical factor. It is helpful but it may not be a critical factor, and more importantly, the systemic effects are very important.
Ari: This, to me, would make sense more in the context of, let’s say, conditions, medical conditions, diseases that are more metabolic in nature, have to do with metabolic health or things going on in the blood. For example, modulating immunological parameters, modulating inflammatory cytokines, and things like that, as opposed to, let’s say, the context of wound healing or treating a joint, for example. You have an arthritic joint and you want to get the light directed into that joint as much as possible, even skin anti-aging, let’s say.
I think the more you look at something like that, the more that you would expect local effects to dominate, whereas if you’re looking at something like chronic fatigue or brain fog or parameters like that, you might expect the systemic effects to be mediating the majority of that. Do you agree with that?
Dr. Arany: I feel there are a lot of context-dependent responses that I don’t think we can capture in a single statement like that. Again, just not to confuse the audience, I think there is a place for generic PBM treatments for wellness specifically. Skin tone, again, we can talk about specific dermatological problems, acne, and wrinkles versus just improving skin tone, hydration of the skin. That could be the simplest measure. I don’t know if we can actually capture the entire thing in a broad statement like that. Overall, I think there is a place for PBM in wellness in general.
Ari: You wouldn’t agree with the statement that there are certain contexts where you would expect the local effects to be more important than the systemic effects or certain contexts where the opposite is true where you would expect systemic effects to be sort of equally effective to treating local areas?
Dr. Arany: If you’re talking about doing a therapeutic treatment, the answer is yes. If you have a wound, treat the wound. That’s an easy treatment. If you’re trying to do molecular resilience in cancer patients before they get chemo-injured, before they get a wound, what do you treat? There is no wound to treat. In that case, I think a systemic response, not just a regional response, but an entire systemic response might be more beneficial.
Ari: Right. That’s exactly what I’m getting at. Even going back to the mechanisms like mobilizing stem cells and having them targeted to a certain area, it almost implies that there is an element of local effects to that. The area that the light is hitting is directing the stem cells to that location, right? Is it just mobilizing stem cells and they’re circulating and they go wherever is needed?
Dr. Arany: If you’re looking, I’m specifically thinking of Dr. Uri Oron’s work, again, a brilliant scientist in the field. Again, among the pioneers in our field. He’s done some really elegant work with liver stem cells for cardiac injury and liver injury and other– I’m sorry, he’s been mobilizing bone marrow stem cells to do healing in distant organ sites, while most of our work has focused on either skin stem cells or tooth stem cells or bone marrow stem cells for bone healing. All those studies are local or regional areas.
I think there is a space for both. What would you like to do? Again, if we have a very clear rationale for what we are trying to accomplish, I think we’ll have better clinical and biological results to actually compare. My work and Dr. Oron’s work are not truly comparable because we are doing very different, not to say that his treatment doesn’t mobilize local stem cells for local healing, but very different data. That’s where I think there is confusion, but I think there’s a place for both.
Ari: There has to be something to the local stem cell aspect of things. If you’re trying to affect stem cells in the mouth, in the gingiva, or in teeth, I would certainly expect researchers to find better effects on those stem cells by shining light here as opposed to shining light on a distant site or using a full body panel and just relying on the systemic benefits. Would you agree with that?
Dr. Arany: I agree with that, but again, it’s, what are you trying to accomplish? I think in both the cases, you’re mobilizing stem cells but the stem cells in a local disease are required right there. Once you mobilize them and there is no requirement in the local area, it goes through the circulation and people have done some very careful studies and shown that bone marrow stem cells mobilized can help with cardiac injury recovery. That means it finds where it is necessary and does what it needs to do.
Ari: Just out of curiosity, most people are used to thinking of stem cells in the context of going to get a stem cell treatment, having someone inject huge numbers of millions of stem cells. How do you think the dose compares of– Obviously, it’s going to be much lower but it’s also something that you could do much more frequently to get a stem cell effect from doing something like photobiomodulation as opposed to once a year or once every few years getting a stem cell treatment in a clinic. How would you conceptualize that comparison?
Dr. Arany: Maybe I would reframe that question a bit in terms of active treatment versus maintenance treatments and I think we have the same answer, which is we believe that maintenance treatments are good for wellness overall, but also to maintain a therapeutic benefit that you’re seeing during active treatment. Should you do it? Again, you don’t want to overdo it, but is it helpful to do it every day? Probably not.
Once or twice a week would be my regular suggestion. Many people are put on once-a-month recalls and that is usually adequate for the PBM part. Of course, there are other parts that you would want to do, which is maybe a good segue into your other interests. You mentioned EMFs and other forms of energy.
Should we be concerned about EMFs from photobiomodulation devices?
Ari: EMFs have gotten a lot of attention in the red light therapies panel space. In particular, there’s a lot of question mark that a lot of people who happen to be health conscious people are very concerned about EMFs from devices. A lot of these companies then market, we have this level of EMFs, we have zero EMFs, at six inches, there is no detectable magnetic fields, and so on. It’s really interesting because if you actually go into the scientific data on that, on exposure to magnetic fields and electric fields in particular, and you look at the established safety guidelines, for example, workers in factories, this is mainly where the guidelines emerge.
For people who have jobs where they’re exposed to high magnetic fields, we’re talking about many orders of magnitude difference in the amounts of magnetic fields and the doses that someone would be exposed to. From what I’ve gathered, there is not compelling data to show a safety concern from a 10 or 20-minute exposure to a device, whether it’s a hairdryer or a red light panel or a blender in your kitchen or something like that. It doesn’t seem compelling. My take on it, my interpretation is that the fears of this EMF exposure from these devices are massively overblown relative to the data we have. I’m curious what your take is on that field.
Dr. Arany: We talked about how we expect that there would be optimization or personalization based on anatomical sites. I think there is a place for different device footprints. For example, if you have pain in your neck, a flat panel is not very helpful. You simply take a curved panel and it will significantly improve your light delivery. You’re not overdosing, you’re not unnecessarily underdosing.
Ari: I’m glad you brought that up. That was something I was going to ask about. Go ahead.
Dr. Arany: I think there is a place and there is a big company that focuses on a laser that goes back and forth, the scanning laser, and tremendous clinical results. I think there’s a place for the device footprint varying based on how you want to deliver. The optimization of that, I think is still, unfortunately, lacking. As I’m going back again, I think we are going back to the same point that it’s easy to change device parameters very easily. What we are not doing yet effectively is how does that affect the biological response and therefore the clinical outcome? Any close to the loop.
Ari: Dr. Arany, I just want to clarify this. The question on EMS is related to exposure to electric and magnetic fields that people have a safety concern with. Separate from the issue of photobiomodulation. People are concerned with, “If I use this LED panel, it’s emitting a magnetic field or an electric field. I’m afraid that magnetic field is going to be harmful to my health.
Dr. Arany: Right, and I think that’s also a concern with cell phones. There’s been a lot of work with cell phones and whether it’s harmful.
Ari: Different types of EMS in the case of cell phones.
Dr. Arany: My lab does a lot of research in the broad field of directed energies. You’re using energy in a directed manner. We have been exploring radio frequencies, ultrasounds, shockwaves, electrical current fields, microcurrent fields. Again, we are doing research. Obviously, we are looking at both the positives and the negatives. We feel that our understanding of where we are with the field is that there are some of these other types of energies that are synergistic with light.
However, there are different types of energies which also antagonize our therapeutic light benefits. It is not like all microcurrent is good, all EMF is good. I think we have to be very careful about the format, the sequence of treatments. Should you do it concurrently? Should you do it before or after? We get asked this all the time. This is, obviously, a little bit of a digression but we get asked whether saunas are also PBM and whether saunas can supplement PBM. As sometimes with the same device. You have these really nice near infrared lamps that people use for sauna, for heating.
Can you just turn it down and do PBM? I think the answer is probably yes, you can, but those are two different treatments. I personally believe, at least in all the studies that we have done, our experience has been that you can do the exact same device for different treatments, and of course, other forms of energies, but doing them concurrently may not be a good idea till we understand exactly what the context is.
Ari: That example of sauna and PBM would seem not to be a good combination by virtue of the fact that heating the superficial tissues brings more blood to the surface tissues, which will block more of the light and prevent more depth of penetration of the photobiomodulation.
Dr. Arany: You can make that analogy with EMF and microcurrents. You can make the same analogy that we don’t understand all of it but you might be doing similar things, let’s say, angiogenesis. There is, obviously, significant evidence with both shockwaves and microcurrents on increasing perfusion. Increasing perfusion need not bring just oxygen and blood flow, it might bring other mediators into the field that you’re doing PBM with. Until we understand the precise context, at the moment, I do not recommend doing it concurrently.
Photobiomodulation wavelengths
Ari: A few more rapid-fire questions. One, you talked about blue light earlier and you showed your chart showed blue and green in almost the way that you’re presenting that information– I’m not saying you said this, but the way that it could be interpreted is that all of these wavelengths are doing the same thing. Would you put blue light in a similar category? Would you put it in the realm of photobiomodulation or do you consider photobiomodulation, really, the realm of the 600s, 800s, and maybe some in the mid-infrared?
Dr. Arany: No, I think currently our understanding is that it is 400 to 1,200. That is the range of PBM effective wavelengths where we have good data. All of those wavelengths have shown therapeutic benefit. There is some nuance between blue light doing disinfection versus blue light doing– I think we discussed this last time, but blue light can be very effective as a disinfectant media, which is PDT, rather than PBM. Blue light can when it’s done at the right dose in use. We have seen this in our studies.
Ari: For example, doesn’t blue light, let’s say on the skin, generally promote more of a harmful effect rather than a skin anti-aging effect like red or near-infrared? Doesn’t it, for example, in the context of the eyes, promote, let’s say, macular degeneration or harmful effects on eye health, whereas we have data to support beneficial effects from red light? Do you think that they’re operating on the same mechanisms?
Dr. Arany: How do I say this? If it were, if PBM was purely absorption dependent, then we would have identified an optimal wavelength by now. I don’t think we have done that in the field. There are people who have successfully used blue light, successfully used green, yellow, red, infrared, and shown that they can actually get– In the same disease, they have shown that they can get therapeutic benefits. Having said that, in the initial part of this discussion, we talked about different targets at different times.
Wound healing, again, a great example. At different points in the wound, from the beginning to the last stage, there are different constituents in that milieu that are responding to light. Initially, you have blood components, then you have vascular tissue, then you have granulation tissue, then you have fibroblasts and epithelial cells. At different phases, you might need different light sources. Our current understanding is that absorption is not adequate to explain how the PBM is working in all these phases.
If you stop thinking about absorption as the only way light can transfer energy, the wavelength becomes less of a concern because all the photobiologists in the field will tell you that if you don’t have absorption, you will not get a response. We are seeing responses with 810, we are seeing responses with 940, 980 where there is minimal absorption with water but we don’t really have good chromophores in that space.
Ari: The fundamental problem with blue is that it doesn’t really penetrate to any significant depth. It stays very superficial.
Dr. Arany: Right, but if your lesion is superficial, that’s where you want that response. If you have a wound, an ulcer, or an erosion, you want to use green or blue because you want that energy in the superficial surface. It is not the same blue.
Ari: Blue light has been shown beneficial in wound healing, similar to how red light has?
Dr. Arany: Depending on how you define therapeutic response. If you just care about the wound healing, yes, it has shown a response. Has the wound healed better because you have removed infection or have you actually promoted the epithelium and the connective tissue? That I think still needs to be dissected out but blue light has shown benefit in the same context that red light has.
Ari: It’s interesting, Michael Hamblin had a very different take on this issue of, for example, devices starting to incorporate blue light and things of that nature. He said, in that case, you’re moving away from photobiomodulation devices and towards more just standard white light. It’s interesting that you have a different perspective on that. Let me ask you, if that’s the case, wouldn’t just exposure to– If basically, all of these wavelengths are essentially having benefits, if we’re moving in the direction of that line of thinking, then wouldn’t, basically, just exposure to sunlight be expected to be the best?
Dr. Arany: We’re not saying that all wavelengths have a beneficial response. We are saying that a particular wavelength at a particular time has the beneficial response. There’s a bit of a nuance in how you interpret that all wavelengths work does not mean all wavelengths should be used concurrently. The sunlight question is fascinating. We get this asked all the time, that if PBM is all about light, why don’t we get the most benefit when we go out in the sunlight? I think we touched about it again a little bit last time.
Sunlight is great for you for many reasons. However, the amount of individual wavelengths are not the same and there is a potential for the wavelengths to interfere with each other in terms of the best response. I think that is the reason why sunlight is not a good source of PBM by itself unless you use filters and stuff. There are people who are trying that. People have tried water-filtered infrared and different kinds of filters for sunlight to get the right wavelength of light. I think there’s a place for that, especially if you’re thinking about sustainable treatments in non-infrastructure, health infrastructure places. Maybe PBM as filters with sunlight-filtered PBM might have a role.
Are heating tissues during PBM treatments harmful?
Ari: I have two last questions for you. One is how big of an issue is heat, heating of the tissues? Do that as a major concern with LED-style devices– Granted lasers, I know it’s a concern, but with typical LED-style devices, do heating of the tissues as a major concern? I’ve seen some people make the argument that any warming of the tissues is a harmful thing. I’ve also seen people, for example, Dr. Hamblin has said no, it’s not an issue. It’s normal for there to be a warming of those tissues. That’s not in any way harmful. It doesn’t mean that you’re negating the benefits of photobiomodulation. The people who are arguing that heating the tissues in any way, to any degree, is harmful are just misinformed. What’s your take on that?
Dr. Arany: My take is, again, very respectfully different based on the data that we are seeing. Here’s a good example of why we think non-thermal treatments are actually PBM. We measured very carefully the amount of heat rise that occurs in the skin of mice. We correlated that with appearance of histological, psychological damage. Even when you get to a temperature of 45 degrees, which is not even warm coffee, 45 degrees is warm, not even hot, you start seeing cellular damage. You start seeing molecular damage.
At that temperature, you’re also inactivating a lot of the ROS scavengers. These are normal enzymes that are present in the tissues to prevent redox from damaging your cells and tissues. At 42 to 45 degrees, you start inactivating the ROS scavengers. Therefore, you start seeing the steep rise in the molecular damage that is occurring in the tissues.
Warmth is great for you. I think anyone who’s been in a sauna will tell you that same thing. Sunlight is great. You feel very nice when you go out. However, that is not PBM. If you’re looking for a PBM, which is a biological response, you should not be causing significant heating. We have evidence at the cellular, molecular, and tissue level in the animal and in patients.
Ari: The temperature that you just gave, the example of was 45 degrees Celsius, right?
Dr. Arany: Right.
Ari: 45 degrees Celsius and Fahrenheit is 113 degrees. In the context of even going into a sauna, skin temperatures would reach maybe 105 degrees. It would be quite significantly below that range.
Dr. Arany: Good point.
Ari: I have no doubt that you can heat tissues enough to create negative effects where you heat them so much you start to get protein degradation and overt signs of harm. The question is, and this also relates to the biphasic dose response thing, the same curve that we see there.
Dr. Hamblin, for example, argues that heating, like getting the tissues really hot, yes, you can absolutely create harm but mild warming of the tissues is not harmful. You said heating is not photobiomodulation, but does that mean that any warming of the tissue in conjunction with administering photobiomodulation in the 600s or 800s, any warming means that you’re creating harm or you’re negating the benefit? Is some warming normal?
Dr. Arany: I personally believe that anything above 45 degrees is negating its benefit. I think that we always talk about a range. I think it’s 42 to 45 degrees to be precise, on the surface, which means that inner temperature, depending on your wavelength, can be higher or lower depending on which wavelength you’re using. I think there is no place for tissue heating in PBM. There is a separate field called hypothermia, which actually does heating, controlled heating, as a therapeutic benefit. I think saunas fall within that hypothermia concept.
Ari: Just to clarify, there is some bit of heating that occurs with using an LED panel or a pad-style device. Do you think that’s harmful?
Dr. Arany: If it is above that particular temperature. Your body temperature is 37, 38 degrees. There is a range–
Ari: It’s not going to be above 45 degrees. It would take a really powerful device to heat the tissues to that hot.
Dr. Arany: I think if you look at the newer devices and lots of the beds, I think a lot of people actually complain of being very hot inside and uncomfortable. I don’t think it’s impossible to get significant heating. Again, depends on your skin type, depends on your body mass, how well-hydrated you are. There are so many parameters that define how bad or how good that light is being perceived. I think it’s not difficult to cause heating, even in a PBM device. More so with a laser, less so with an LED, but it’s definitely possible, especially with the new high-power LEDs. It is not difficult to generate heat but you’re negating your benefits.
Ari: You’re negating the benefits even if it’s mild warming that’s just feels pleasant warming of the tissue or only when you get to really uncomfortably hot?
Dr. Arany: Uncomfortably hot.
Ari: Perfect.
Dr. Arany: If any person is feeling uncomfortable or feeling hot, then there is a problem. If they’re feeling warm, that’s a sign that either you back off or you stop treatment.
Ari: Dr. Hamblin would definitely agree with that. Dr. Arany, we both have to go at this point. Thank you so much for this time. I might ask you for another conversation, but first, I want to give you an opportunity to speak to our audience, let them know about the research you’re doing in the lab and how they can contribute to it.
Dr. Arany: I think this is a field that has tremendous potential for biomodulation. Unfortunately, although a lot of research is being done, it is not being done at the highest level of support because the field, as a whole, has not been recognized. It is getting there rapidly. This is one field where the clinical evidence actually has gone way ahead of the research. Surprisingly so, because there are things that no other treatment can benefit that this treatment is being shown either as an adjunctive care or as palliative. It is definitely a mainstream.
We do a lot of research in trying to understand how this treatment works and how we can optimize it. If you’re interested in supporting it, I think Ari will provide a link to the research that can be supported in this field. We do both clinical research and basic science research but with the goal of optimizing treatments for a large range of diseases.
Ari: What is the link or what can people search for to arrive at the place where they can donate to your lab’s research?
Dr. Arany: There is a University at Buffalo Giving site. I can send you the link or I think already been.
Ari: We’ll post it. I just want people to know that I have no affiliate link here. I make no money. I have no financial incentive for people to donate to you. I just want to clarify that. Having said that, I highly encourage everybody listening to Dr. Arany to donate to the lab. He’s doing amazing research. He’s also been, these conversations have been enormously helpful to me personally in updating my own knowledge and the knowledge I’m going to put in the upcoming version of my book, The Ultimate Guide To Red Light Therapy, and I’m going to be making my own personal donation to his lab and the research they’re doing as a thank you for that.
I think more broadly, he’s making an amazing contribution to this whole field of photobiomodulation. If you appreciate that, it’s a wonderful thing that you can do to donate directly to the researchers so you can help fund further research and expand the knowledge for generations to come. We’ll put the link in the podcast description. For people listening, Dr. Arany, do you have it offhand? Can you say what the link is, just so for people listening who may not be able to go to click on something?
Dr. Arany: If you go to ‘UB Giving,’ you’ll come to this page, and then you hit ‘Give Online.’
Ari: Go to ‘University at Buffalo Giving,’ find your cause, and then at the top right, there’s a tab or a button that says ‘Give Online.’ Click that.
Dr. Arany: Then if you look for ‘Search for more,’ you’ll find it here.
Ari: ‘Search for more.’ Do it there? ‘Search for more,’ and then ‘Photobiomodulation.’
Dr. Arany: ‘Photobiomodulation Therapy Fund.’
Ari: There we go, ‘Photobiomodulation Therapy Fund.’ The website, if people want to go directly, is ubfoundation.buffalo.edu/giving/index.php or you can follow the screen share and the guidance that we just took you through. Go to ‘University at Buffalo Giving,’ click on that, find your cause, click the button on the top right, ‘Give Online,’ and then you got to go to the search bar for ‘Photobiomodulation Fund.’ I highly encourage all of you to make a donation. Again, it’s a wonderful thing that you can do, not only for Dr. Arany and his researchers and the students who work under him but, really, for humanity more broadly to just facilitate more knowledge in this important field.
Dr. Arany, thank you so much for your time. It was an absolute pleasure. I’m grateful for all of your astounding knowledge and I really appreciate you sharing it with me and my audience.
Dr. Arany: Thank you so much for having me, Ari. I enjoyed that conversation.
Show Notes
00:00 – Intro
00:36 – Guest Intro
04:30 – The biggest issue with photobiomodulation
09:43 – Photon Fluence
15:27 – How different wavelengths penetrate tissue
21:29 – Difference in treatment time and dose
35:22 – The biphasic dose response in PBM
40:15 – LED panels or laser devices?
57:54 – Optimizing red light therapy
1:23:16 – Should we be concerned about EMFs from photobiomodulation devices?
1:29:38 – Photobiomodulation wavelengths
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